Power-lift mechanism



F. T. BLAYDES POWER-LIFT MECHANISM April 6, 1954 2 Sheets-Sheet l Filed Nov. 16, 1949 IOM (D, FW

April 6, 1954 F. T. BLAYDES POWER-LIFT MECHANISM 2 Sheets-Sheet 2 Filed NOV. 16, 1949 Patented Apr. 6, i954v POWER-LIFT MECHANISM Frederick T. Blaydes, Canton, Ill., assignor to International Harvester Company, a corporation of New Jersey Application November 16, 1949, Serial No. 127,563 i 7 Claims. 1

This invention relates to agricultural implements and particularly to lifting mechanism therefor. More specifically, the invention concerns lifting mechanism for an agricultural implement incorporating means for lifting the implement to a constant height irrespective of variations made in the operating position of the implement.

In an agricultural implement such, for example, as the tractor-mounted cultivator with which this invention is concerned, it is frequently necessary to adjust the operating depth of the cultivator shovels in the ground and it is also important that when the implement is raised to its transport position it be lifted to the same height every time. Before the advent of constant height lifting devices for implements a cultivator shovel which was adjusted to operate at its maximum depth in the ground would not be raised as high upon the machine by which it was transported as would be the case if the shovels were operating at a shallower depth.

An important object of the present invention is to provide an improved constant height lift for a tractor-mounted implement.

Another object of the invention is to provide in an agricultural implement an improved means for adjusting the depth of operation of the implement while assuring the lifting of the implement to a constant height above the ground irrespective of the operating depth of the tools.

Another object of the invention is to provide for use in combination with a hydraulic ram unit, mechanism utilizing the full stroke of the ram unit in raising' the implement in transport position while providing means for adjusting the implement independently of the ram unit.

Other objects and advantages of the invention will become clear from the following detailed description when read in conjunction with the accompanying drawings wherein:

Figure l is a view in side elevation of a tractor having mounted thereupon partly in section a cultivator adapted to be raised and lowered by mechanism incorporating the features of the present invention and showing in dotted lines an adjusted position of the implement.

Fig. 2 is a plan view of a portion of the structure shown in Fig. 1 with parts removed for clarity illustrating only one side of the tractor.

Fig. 3 is a view in perspective of the lifting mechanism of this invention.

Referring to the drawings, the tractor incorporating the present invention is designated by the. numeral I and is provided with a pair of sar-46.55)

spaced rear drive wheels I I (only one of which is shown), front wheels I2, and a power plant I3.

The front end of the tractor at each side thereof is provided with a plate III to which is aixed a laterally extending square tool bar I5 having mounted thereupon one or more spaced brackets I6. Each of the brackets I6 has pivotally connected thereto at vertically spaced locations a pair of generally parallel links I1 and I8, the rear ends of which are pivotally connected to an upstanding bracket I9 to the base of whichdis connected a tool gang 20 carrying cultivator shovels 2 I.

Each pair of parallel links I'I and I8 is raised and lowered with respect to the tractor in order to move the tool gangs between operating and transport positions by a rod 22 connected to the bracket I9 at its lower end and having its upper end slidably received in a swivel 23 carried at the end of an arm 2li mounted upon a bail 25 pivotally mounted at one end upon the end of toolbar I5 and at its other end secured to a generally upwardly and rearwardly extending lever arm 26 pivoted at 2l' upon the plate I4. The upper end of rod 22 is provided with an adjusting nut 28.' A spring 29 surrounds the rod 22 between swivel 23 and the nut 28 and another spring 3B surrounds the rod between the swivel 23 and a collar 3 I. These springs serve as hold-down springs and to absorb shocks to the tool in transport position.

Lifting power for vertically moving the tool gangs between operating and transport positions is provided by a hydraulic ram unit 32. This unit is preferably of the one-way type and receives fluid under pressure through a hose line 33 from a source, not shown, receiving power from the tractor power plant. Ram unit 32 comprises a cylinder 3 pivotally mounted at 35 upon a bracket 36 aixed to the side of the tractor. A piston rod 3l is slidable in the cylinder and is receivable for relative sliding movement in a tube or sleeve member 33 supported at one end in trunnion 39 carried by the lever 26.

Upon forcing iiuid under pressure through hose 33 into the cylinder 3.@ piston 31 is extended until the end thereof engages a stop or abutmentr in the form of a pin 49 extending through the sleeve 33 in one of several openings 4I provided therein Ifor this purpose. At this point it should be clear that upon extension of the piston in the cylinder until the end thereof engages pin 40 the lever 26 will be rocked forwardly, rocking the bail 25 and through rod 22 lifting the parallel links I1 andfl 8 and the tool gangs supported thereby. The tools are raised until the ram unit has reached the end of its stroke and the working tools are in transport position. Upon return of the liuid to the tractor source the piston rod 3l is retracted within the cylinder and away from contact with the pin 4B.

A manual adjustment for the operating depth of the tools in the ground is provided by mechanism which includes an adjusting member or lever 42 pivoted at 43 upon the bracket 3e and provided with a detent @il engageable in notches 45 in a quadrant lli provided at the upper end of the bracket 35. en arm @il or the lever on the opposite side or the pivot :i3 is connected by a rod 43 with a rock arm is secured at its lower end to a sleeve 5S mounted upon a pin 5i secured to the plate i6 and braced by an angle member 52.

Another pin 53 vertically spaced above pin 5l is carried by rock arm @9 and its end is braced by a strap 5t connecting the ends of pins 5l and 53. A spacer 55 surrounds the pin 53 and has secured thereto as by welding one arm lili of a crank El' pivotally connected at 58 to a link 59 comprising a pair of link members t and 6|, the rearward ends of which are pivoted upon a pin S2 carried upon a lug 't3 secured to lever 26. Links 51 and 5S thus form an articulated connection between the rock arm fl and the lever 2S.

Another arm 'li-4 of the crank 5l extending on the other side of pivot 58 is connected by an extension spring S5 with a lug Se secured to the link 58 between the members 63 and ill.

In the position of the parts shown clearly in Figs. 1 and 3, the pivot pin Sil is above a line drawn between the pivot axes of the pins 53 and 62. The spring Se tends to urge the pivot 53 toward this center line thus urging lever 26 rearwardly and tool gangs 2e downwardly. A stop is provided in the form of a pin 5l carried between the ends of link members 35 and 6l on the side of pivot 58 opposite the pin S2 and this pin til is arranged to engage the upper edge of the crank 5i to lirnit the downward movement of the pivot 58. Movement or" the rock arm de, therefore, to adjust the implement to selected positions by manipulating the adjusting lever e2 is transmitted through the linkage formed by the crank 5l and link 59 to the lever 2S to move the latter forwardly or rearwardly and thus affect the operating depth of the cultivator shovels 2l. At the same time, lfloating movementv of the shovels 2l is accommodated and when piston rod 3l in cylinder Sli is extended to rock the lever 2S forwardly, this is accomplished against the action of the spring B5, crank 5l pivoting about the pin 53 and moving away from the stop formed by the pin S1.

Since the piston rod 37 is not connected to the lever 28 and raises the implement by virtue of its engagement with the pin dil in the sleeve 3, andl further, since the piston rod 3l is retracted within the cylinder 3d when the implement is in its operating position, the operator is free to adjust the depth and move the lever 2:31, and with it the sleeve 38, with respect to the cylinder and the piston to adjust the operating depth of the earthworking tools. Regardless of the depth setting of the tools, the stroke of the piston 3l in the cylinder remains the same and the height of the tools in transport position remains the same. This height may be varied somewhat by placing the pin stop 40 in another of the openings di in the sleeve 38.

It is believed that the constant height liftmechanism of the present invention will be clearly understood from the foregoing description. Modifications, however, may be made Without departing from the spirit thereof or the scope of the appended claims.

What is claimed is:

l. In lift mechanism for a tractor-mounted implement, a lifting lever pivoted on the tractor and connected to the implement, a power cylinder mounted on the tractor having a piston rod, a connection between the piston rod and the lever comprising guide means on the lever adapted to slidably receive and guide the said piston rod, a stop in said connection engageable by said rod during extension thereof to raise the implement to an extent determined by the stroke of the piston, said piston rod being retractable out of engagement with the stop to lower the implement, and means for moving the lever and therefore the stop independently or" the cylinder and piston to vary the operating,r depth of the implement without altering the stroke of the piston. and therefore the height to which the implement is lifted comprising a rock ann on the tractor, means for selectively adjusting and holding said rock arm in positions corresponding to changes in operating depth of the implement, and connecting linkage between said rock arm and saidlever for transmitting adjustment of the rock arm thereto.

2. In lift mechanism for a tractor-mounted implement, a lifting lever pivoted on the tractor and connected to the implement, a power cylinder mounted on the tractor having a piston rod, a connection between the piston rod and the lever comprising guide means on the lever adapted to slidably receive and guide the said piston rod, a stop in said connection engageable by said rod during extension thereof to raise the implement to an extent determined by the stroke of the piston, said piston rod being retractable out of engagement with the stop to lower' the implement, and means for moving the lever and therefore the stop independently or" the cylinder and piston to vary the operating depth of the implement without altering the stroke of the piston and therefore the height to which the implement is lifted comprising a rock arm on the tractor, means for selectively adjusting and holding said rock armin positions corresponding to changes in operating depth of the implement, and connecting linkage between said rock arm and said lever for transmitting adjustment of the rock arm thereto, said connecting linkage comprising articulated links to accommodate lifting of the implement independently of operation of said rock aim.

3.111 lift mechanism for a tractor-mountedy implement, a lifting lever pivoted onthe tractor and connected to the implement, a power cylinder mounted on the tractor having a piston rod, a connection between the piston rod and the lever comprising guide means on the lever adapted to slidably receive and guide the said piston rod, a stop in said connection engageable by saidrod during extension thereof to raise the implement to an extent determined by the stroke of the piston, said piston rod being retractable out of engagement with the stop to lower the implement, and means for moving the lever and therefore the stop independently of the cylinder and piston to vary the operating depth of the implement without altering the stroke of the piston and therefore the height to which the im-l plement is lifted comprising a rock arm on the tractor, means for selectively adjusting and holding said rock arm Vin positions cori-.espondi ing to changes in operating depth of the implement, and a connection between said rock arm and said lever for transmitting adjustment of the rock arm thereto, said connection including pivoted links and a stop to prevent the movement of the pivotal connection therebetween over a center line between the connections of the links to the lever and the rock arm.

4. In lift mechanism for a tractor-mounted implement, a lifting lever pivoted on the tractor and connected to the implement, a power cylinder mounted on the tractor having a piston rod, a connection between the piston rod and the lever comprising guide means on the lever adapted to slidably receive and guide the said piston rod, a stop in said connection engageable by said rod during extension thereof to raise the implement to an extent determined by the stroke of the piston, said piston rod being retractable out of engagement with the stop to lower the implement, and means for moving the lever and therefore the stop independently of the cylinder and piston to vary the operating depth of the implement without altering the stroke of the piston and therefore the height to which the implement is lifted comprising a rock arm on the tractor, means for selectively adjusting and holding said rock arm in positions corresponding to changes in operating depth of the implement, and a connection between said rock arm and said lever for transmitting adjustment of the rock arm thereto, said connection including pivoted links and a stop to prevent the movement of the pivotal connection therebetween over a center line between the connections of the links to the lever and the rock arm and a spring urging the pivotal connection between said links to said center line.

5. In lift mechanism for a tractor-mounted implement, a lever carried by the tractor and connected to the implement, said lever being movable to raise and lower the implement, a guide member having an abutment carried by the lever and movable therewith, a power cylinder on the tractor deriving power therefrom, a piston rod in the cylinder slidably receivable in said guide and engageable with said abutment to move the lever and raise the implement in response to extension of the piston rod, and means for adjusting the lever independently of the cylinder and piston to regulate the operating position of the implement, comprising a rock arm carried by the tractor, an adjusting member mounted on the tractor and operatively connected to the rock arm for selectively adjusting the position of said rock arm relative to the lever and holding it in adjusted position, and a connection between said arm and said lever for regulating the operating position of the implement in response to actuation of said adjusting member comprising connecting link means capable of transmitting motion from the rock arm to the lever, but yieldable to accommodate independent movement of the lever.

6. In lift mechanism for a tractor-mounted implement, a lever carried by the tractor and connected to the implement, said member being movable to raise and lower the implement, a

guide member having an abutment carried by the lever and movable therewith, a power cylinder on the tractor deriving power therefrom, a piston rod in the cylinder slidably receivable in said guide and engageable with said abutment to move the lever and raise the implement in response to extension of the piston rod, and means for adjusting vthe lever independently of the cylinder and piston to regulate the operating position of the implement, comprising a rock arm carried by the tractor, an adjusting member mounted on the tractor and operatively connected to the rock arm for selectively adjusting the position of said rock arm relative to the lever and holding it in adjusted position, and a connection between said arm and said lever for regulating the operating position of the implement in response to actuation of said adjusting member comprising a pair of articulated links pivotally connected to said arm and said lever, and spring means for resisting relative pivoting of said links in one direction.

7. In lift mechanism for a tractor-mounted implement, a lever carried by the tractor and connected to the implement, said lever being movable to raise and lower the implement, a guide member having an abutment carried by the lever and movable therewith, a power cylinder on the tractor deriving power therefrom, a piston rod in the cylinder slidably receivable in said guide and engageable with said abutment to move the lever and raise the implement in response to extension of the piston rod, the position of the abutment in said guide being adjustable to vary the effective stroke of said piston, and means for adjusting the lever independently of the cylinder and piston to regulate the operating position of the implement, comprising a rock arm carried by the tractor, an adjusting member mounted on the tractor and operatively connected to the rock arm for selectively adjusting the position of said rock arm relative to the lever and holding it in adjusted position, and connecting linkage between said arm and said lever for regulating the operating position of the implement in response to actuation of said adjusting member.

References Cited in the i'lle of this patent UNITED STATES PATENTS Number Name Date 2,156,570 Lindgren May 2, 1939 2,283,377 Lindgren et al. May 19, 1942 2,309,203 Morkoski Jan. 26, 1943 2,319,492 Dewey May 18, 1943 

